When start emacs, it complains. and there is no ido-mode.
How to fix this?

error: "Unknown req `min-colors' with options `(88)'"
To ensure normal operation, you should investigate the cause
of the error in your initialization file and remove it. Start
Emacs with the `--debug-init' option to view a complete error
backtrace

2 Answers
2

I have the same problem. We're upgrading to RHEL5, so I assume we'll have emacs 21 for a long time. Luckily the EmacsWiki has a link to an older version. It's over a decade old, but it's better than nothing.

It seems to work fine, but some of the constants have different names. For example, I had set ido-default-file-method to selected-window, but the latter is named same-window in the older version of the code.

Emacs 21.1.1 is fairly ancient (21.1 was released almost exactly 10 years ago). Upgrade to a more recent version, and you should be fine (unless it no longer builds on AIX?) Lots of people are using the not-yet-final version 24, but 23.3 is the current stable release.

ido is also a standard part of Emacs, these days, so you should be able to get rid of your copy of that.

Admittedly you may well encounter other upgrade incompatibilities by taking this approach, but that issue will surely only get worse as time goes on...